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Oxygen Sensor Emulator

Discussion in 'DIY (Do-It-Yourself)' started by brucehowe, Jan 23, 2019.

    • Member

    brucehowe

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    Hey Gang,

    Need some help with my 09 128i.
    Year and a half ago installed AFE headers and cats as a lower cost alternative to OEM parts.
    Was warned that I may get codes from downstream O2 sensors.
    Was resetting and no service engine light for several months.
    Now, light comes on a few miles after reset.

    Has anyone had experience with an oxygen sensor emulator that prevents the codes?
    Another alternative would be a spacer to set the sensor further back from the stream, but I'm not sure there would be enough room.

    Any insight would be most helpful.

    Thanks so much,
    Bruce
    • Member

    MGarrison

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    I haven't heard of an 02 sensor emulator, but, wouldn't be surprised they exist, theoretically or even technically doesn't seem like it would be that hard to have something outputting the voltage or voltages equivalent to stoichiometric a/f ratio. What I'm wondering is why codes start triggering after so long not triggering - what could have changed...?
    • Member

    brucehowe

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    I generally look for advice but am seldom in a position to give it, so:

    A follow up after 500 miles with no codes, in case someone else has this problem.

    Codes were P0420 & P0430: Catalyst System Efficiency Below Threshold.

    Sensors passed all tests on reader. No other problems.

    aFe headers and cats were less restrictive. Logic is they are not as efficient and moving sensors a bit out of stream will fool them. Local auto parts guy said spacers work more often than not.

    I went for: UroTuning O2 Sensor Spacer. A bit pricey, but well made (not that that matters much). More important, the angle and long thread with lock nut seemed to offer more flexibility in a tight location. UroTuning claimed about an 80% success rate.

    Well, I got through emissions inspection. And, by putting together a drive cycle of my own after looking at others, I was able to get all systems in a state of readiness after less than 30 miles.

    Hope this helps someone else out.


    MGarrison likes this.
    • Member

    MGarrison

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    Thanks for the update, glad you got it worked out!

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